P. F. Clark

A Bacteriophage Active Against a Virulent Hemolytic Streptococcus.

We reported 1 last year the finding of a bacteriophage against a virulent hemolytic streptococcus. Such a lytic principle active against streptococcus has been reported so rarely, if at all, that it seems desirable to state our results in some detail. The organism against which the phage was originally active was isolated about 3 years ago from a spontaneous fatal infection in a stock rabbit. At autopsy, the animal showed marked thoracic lesions, myocarditis, pericarditis, bronchopneumonia, fibrino-purulent pleurisy, extensive empyema with relatively little grossly noticeable below the diaphragm save an acute splenic tumor. The organism was readily obtained in pure culture from these lesions and also from the hearts blood. It grows on sheep blood agar as a very moist, translucent, mucoid colony, somewhat similar to that of Pneumococcus mucosus, but it produces a wide zone of hemolysis on the plate. One cc. of a 12 hour broth culture will cause complete hemolysis of a 5 per cent suspension of washed sheep red blood cells when incubated for one hour at 37° C. It does not ferment inulin and is bile insoluble, so we consider it an example of a Streptococcus mucosus. It closely resembles the organisms found in cases of septic sore throat. The various fermentation reactions are recorded in Table I. The organism is Gram positive, but is more readily decolorized than many streptococci, and, frequently, partially decolorized cocci may be observed in a chain of Gram positive organisms. It appears in chains of moderate length, the individual members of the chain usually being spherical and variable in size. Capsules can be readily demonstrated by any of the commonly used methods. This organism proved virulent for other rabbits, causing a fatal septicemia in 5 to 7 days, when injected intravenously into full grown animals in amounts of .001 cc. of a broth culture.

Influence of Pantothenic Acid Deficiency on Resistance of Mice to Experimental Poliomyelitis.

Conclusions In 2 series involving a total of 348 Swiss mice, those fed a synthetic ration deficient only in calcium pantothenate exhibited a definite increased resistance to Theilers encephalomyelitis, but little or none to the Lansing strain of poliomyelitis.

Influence of Thiamine Deficiency in Macaca mulatta on Susceptibility to Experimental Poliomyelitis.

Summary The influence of thiamine deficiency on the susceptibility of M. mulatta to experimental poliomyelitis has been studied in 40 animals. The results indicate that this species, when deficient in thiamine, does not exhibit an increased resistance to poliomyelitis virus in contrast to the well-demonstrated resistance of Swiss mice similarly fed.1, 8

Influence of hyper and hypothyroidism on susceptibility of mice to infection with Lansing poliomyelitis virus.

Summary The influence of hyper- and hypothyroidism upon susceptibility of mice to infection with Lansing poliomyelitis virus has been studied. In one series hypothyroidism seemed to favor a higher incidence of paralysis, but this was not substantiated in two other series. The only consistent deviation from the normal course of infection was an increased incidence of deaths without previous signs of paralysis in hyperthyroid mice.

Effect of Amino Acid Imbalance on Course of Lansing Poliomyelitis in Mice.

Summary 1. A decreased susceptibility to Lansing poliomyelitis, characterized by prolonged incubation and survival times, has been observed in mice fed excess methionine. To obtain this effect fully, a continuous period of high methionine intake was necessary prior to inoculation. 2. The addition of excess methionine to low tryptophan rations containing 6-methyl tryptophan resulted in a more marked protection against Lansing infection in mice than when the same amounts of methionine or 6-methyl tryptophan were fed alone.

Effect of minerals on susceptibility of Swiss mice to Theiler's virus.

Summary The influence of the level of 6 common minerals on the susceptibility of Swiss mice to Theilers GDVII virus has been investigated in more than 1100 animals. No demonstrable effect on the susceptibility to this infection was found by varying the level of calcium, magnesium or chlorine in the diet, some effect was noted with sodium, while striking results were obtained with potassium and phosphorus. A progressively decreased resistance was observed as the amount of potassium or of phosphorus was increased in the diets up to the optimal levels.

Influence of pyridoxine, inositol, and biotin on susceptibility of Swiss mice to experimental poliomyelitis.

Summary The influence of pyridoxine, inositol, and biotin deficiencies on the susceptibility of mice to experimental poliomyelitis has been studied in more than 1400 animals. No striking or consistent difference with reference to susceptibility to either Lansing strain poliomyelitis or Theilers encephalomyelitis was noted between animals fed diets deficient or optimum in these vitamins.

Influence of Low Tryptophan Diets Containing 6-Methyltryptophan on Oral Infection with Poliomyelitis Virus.

Summary These experiments are obviously of a preliminary nature but they do show that the susceptibility of a primate to poliomyelitis via a natural portal of entry may be altered and they suggest that this approach to the modification of susceptibility to poliomyelitis should be explored further.

Acid ceramidase and its inhibitors: a de novo drug target and a new class of drugs for killing glioblastoma cancer stem cells with high efficiency

Glioblastoma remains the most common, malignant primary cancer of the central nervous system with a low life expectancy and an overall survival of less than 1.5 years. The treatment options are limited and there is no cure. Moreover, almost all patients develop recurrent tumors, which typically are more aggressive. Therapeutically resistant glioblastoma or glioblastoma stem-like cells (GSCs) are hypothesized to cause this inevitable recurrence. Identifying prognostic biomarkers of glioblastoma will potentially advance knowledge about glioblastoma tumorigenesis and enable discovery of more effective therapies. Proteomic analysis of more than 600 glioblastoma-specific proteins revealed, for the first time, that expression of acid ceramidase (ASAH1) is associated with poor glioblastoma survival. CD133+ GSCs express significantly higher ASAH1 compared to CD133- GSCs and serum-cultured glioblastoma cell lines, such as U87MG. These findings implicate ASAH1 as a plausible independent prognostic marker, providing a target for a therapy tailored toward GSCs. We further demonstrate that ASAH1 inhibition increases cellular ceramide level and induces apoptosis. Strikingly, U87MG cells, and three different patient-derived glioblastoma stem-like cancer cell lines were efficiently killed, through apoptosis, by three different known ASAH1 inhibitors with IC50s ranging from 11–104 μM. In comparison, the standard glioblastoma chemotherapy agent, temozolomide, had minimal GSC-targeted effects at comparable or even higher concentrations (IC50 > 750 μM against GSCs). ASAH1 is identified as a de novo glioblastoma drug target, and ASAH1 inhibitors, such as carmofur, are shown to be highly effective and to specifically target glioblastoma GSCs. Carmofur is an ASAH1 inhibitor that crosses the blood-brain barrier, a major bottleneck in glioblastoma treatment. It has been approved in Japan since 1981 for colorectal cancer therapy. Therefore, it is poised for repurposing and translation to glioblastoma clinical trials.

Abstract 2526: Regulation of angiogenic factors in glioblastoma progression

Background & Purpose: Glioblastoma is the most malignant primary brain tumor in humans and has a very low survival rate. The aggressiveness of this cancer can be attributed to the presence of glioblastoma stem cells (GSC), which are highly invasive and therapy resistant. Increased aggressiveness of GSCs is attributed to the release of angiogenic factors, which promotes the formation of new blood vessels that enhances tumor cell survival and proliferation. The neovascularization also provides a scaffold for tumor cells to migrate, enabling metastasis. Therefore, identifying the altered expression of angiogenic factors is of clinical importance. In this study, we examined the changes in the expression of pro-angiogenic factors in GSCs as compared to the original tumor from which they were derived. We also determined if differentiation of GSC towards a less invasive phenotype decreased the levels of these pro-angiogenic factors. Methods: GBM tumor cells were grown in complete media containing 10% Fetal Calf Serum (FCS) and GSCs were grown in media containing B27, heparin, EGF, and FGF. GSCs were differentiated by growing them in media containing 10% FCS and B27 with vitamin A, for about one week. We examined the expression of a panel of pro-angiogenic factors in GSCs (33-GSC) and in the original tumor cells (33-T) from which GSCs were derived. We then examined if differentiation of 33-GSC decreased the levels of these pro-angiogenic factors. Changes in protein levels were evaluated by immunofluorescence staining. The mRNA levels were quantitated using real time Q-PCR. Results: Immunofluorescence staining showed that the GSCs express higher levels of pro-angiogenic factors examined (11 out of 16). GSCs were successfully differentiated into astrocytes as indicated by morphology and GFAP expression. The differentiation of GSCs into astrocytes was sufficient to cause decreased expression of VEGF and c-MYC. Our data showed 27 fold increase in VEGF mRNA levels, 63 fold increase in MMP2 mRNA levels, 11 fold increase in MMP9 mRNA levels, and 2 fold increase in c-MYC mRNA levels in GSCs compared to the tumor line, indicating the regulation of these pro-angiogenic factors at transcriptional level. Conclusions: Increased expression of pro-angiogenic factors in GSCs may render these cells to be more aggressive and invasive, and suggests that differential expression of angiogenic factors in GSC cells may play an important role in the GBM progression, and therapy resistance. Citation Format: Carolina Larrain, Umadevi V. Wesley, Paul Clark, John S. Kuo, Robert Dempsey. Regulation of angiogenic factors in glioblastoma progression. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2526.